SMT Proximity Sensors Integrate Touch Switches

Promising to make mobile devices more user-friendly and energy-efficient, the SFH7740 and SFH7741 surface-mount proximity sensors use distance measurements to detect a device’s operating status without physical contact to the sensor itself. This technology allows for automatic shutoff of displays and keypads when not in use. The SFH7740 with optical touch switch measures 3.7 mm x 3.7 mm x 1 mm and reacts to distances between 0.5m and 4 mm. Depending on whether the slider is closed or open, the sensor switches display lighting off or on. The SFH7741 reacts at a typical working distance of 20 mm and is suitable for a wide range of applications. For example it can detect when a phone moves close to the ear, taking the display and the keypad out of sight of the user. Both sensors draw an operating current of about 50 µA. For prices, call OSRAM OPTO SEMICONDUCTORS, San Jose, CA. (888) 446-7726.